1. Field of the Invention
The present invention relates generally to devices for pulling conduit or pipe and more particularly with an expandable device secured to the interior of a conduit or pipe that can be engaged by a pulling device.
2. Description of the Prior Art
Numerous pipe pulling and replacement devices are known that are primarily directed to the removal and replacement of larger sections of pipe or conduit generally greater than 6 to 10 inches in diameter. Representative of those devices are U.S. Pat. Nos. 4,637,756; 4,787,463; 5,048,793; and 5,174,664.
Replacing or installing new small diameter pipe or conduit such as water lines has not been practically accomplished by the use of special equipment. This type of conduit is generally installed by drilling or boring an opening of about 4 inches in diameter when pipe up to 2 inches in diameter is to be installed. The leading end of the pipe is then installed into such an opening and tied onto a rope or cable that has been extended from the other side of the opening for engagement therewith. Installation proceeds by several individuals on the far end of the cable pulling while one or more individuals on the pipe engaging end of the cable feed and force the pipe to the extent possible through the opening.
As is obvious, such an installation procedure is difficult, tiring, inefficient and time consuming. Moreover, no device or fixture has been available to secure the end of the pipe in a manner that will not engage the wall of the opening and thereby impede its movement. Consequently, no exceptional amount of force can be used in pulling the pipe from the opposite end of the opening because of the lack heretofore of a suitable connecting element joining the pulling cable to the pipe end. It is with these problems in mind that the present invention has been developed.